Advanced Materials Research Vols. 941-944

Abstract: This paper was concerned with the effects of ultrasonication on the gelation behavior of silk fibroins (SF), and a comparison of Domestic and Wild silkworms was studied. The results show that: with the increase of ultrasonic power, the gelation time of domestic (Bombyx Mori) SF solution decreased sharply. But wild silkworms (Antheraea yamamai and Antheraea pernyi) SF were different, When the power of utrasonication was lower than 400-500 W, the velocity of gelation were accelerated, and when the ultrasonic power was higher than 400-500W, the gelation time were delayed. Whatever domestic or wild silkworms, the mechanism of the effects of ultrasonication on the gelation behavior was that the ultrasonication promoted the structural transformation of SF molecules from random coil or α-helix to β-sheet.

Abstract: It is showed that in the buffer solution of Borax-HCl (pH=6.00), the presence of LU could quench the fluorescence of OFLO, and the quenched level is linear with the concentration of luteolin in a certain range. The detection limit of luteolin is 1.27×10^-9g·mL^-1.The linear range of luteolin is 2.00×10^-7- 8.00×10^-5mol·L^-1 with R =0.9955. The average recovery is 99.2%, RSD = 0.75% . The average content of luteolin in honeysuckle is 212.0μg·g ^-1. At the same time, its mechanism is discussed by resonance light scattering and absorption spectra. Compared with other analysis methods for Luteolin which have been reported,this method has a relatively wider linear range and higher sensitivity.

Abstract: The fermentative kinetic properties of different batches from the red yeast mutant strain GL-5 with high productive β-carotene were investigated by using a 5-L fermenter. Based on the Logistic equation and the Ganden classification, the kinetic models for the cell growth, base material consumption and yield of product were obtained. These mathematic models were in good consistent with the experimental values, and could provide theoretic basis for controlling and further pilot fermentative production of β-carotene from this mutant strain GL-5.

Abstract: Orthogonal experiment optimization of microwave-assisted extraction (MAE) conditions of total flavonoids from Magnolia liliflora petals with the factors of ethanol concentration, extraction time,microwave power,solid/liquid ratio on the yield of total flavonoids were studied. The results showed that optimum extracting conditions of total flavonoids from Magnolia liliflora were as follows: adding 1:10 g·mL-1 of 40% alcohol and extracting for 5 min,microwave irradiation power 464W, under the optimal conditions, the maximal yield of flavonoids was of 2.08%.

Abstract: This study focuses on cold-pressed oil cakes of camellia and bancoul nut seeds, studying the fractal characteristics of pore microstructure of these two oilseed cakes. Combined with the fractal theory, the Darcy law and Hagen-Poiseuille formula were applied to establish a fractal permeability model of oil seed cakes. Cold press was used to determine permeability of oil cakes of camellia and bancoul nut seeds. The calculated values obtained through the model were compared to the experimental values. The relative average errors for camellia and bancoul nut oilseed cakes were 11.7% and 8.7%, respectively.

Abstract: The R. glutinis NR98 of high-producing β-carotene was treated by ultra high pressure (UHP) of 100~500 MPa for 10~30 min. The survival curve of NR98 treated for 10 min was saddle, which shows that the effect of UHP on this strain maybe was the cumulation of many biology effects. The rate of β-carotene production from mutant G39 (obtained at 300 MPa for 10 min) was increased by 59.87% compared with the initial strain NR98, and its genetic quality was proved to be stable by experiments. The result of restriction fragment length polymorphism analysis suggested that mutant strain G39 was likely to change in nucleic acid level.

Abstract: Tung oil monoglyceride (TOM, also called eleostearic acid monoglyceride, EAM) is a derivative of a Chinese renewable natural resource Tung oil and it is a potential monomer for polyurethane which can improve the performances of polyurethane coating. The synthesis of TOM by esterification of eleostearic acid and solketal with catalyst p-toluenesulfonic acid was investigated. Experimental results showed that the suitable synthetic conditions for TOM were as follows: a. for the esterification of eleostearic acid and solketal, with regard to eleostearic acid 0.02 mol with concentration 0.5 mol/L, mole ratio of eleostearic acid to solketal 1:1.5, catalyst p-toluenesulfonic acid dosage 5% (wt, calculated by eleostearic acid), dehydrating agent xylene, and reaction time 3 h under refluxing. The conversion of eleostearic acid peaked at 99.1% under the optimal conditions and the intermediate, solketal eleostearate was obtained. b. after deprotection under acidic condition for 4 h at 35 °C to remove protection agent acetone which was employed in the synthesis of solketal, the product TOM would obtained with yield 93.6%.

Abstract: Key odor compounds in different edible parts (abdomen, claw, leg meat and gonad) of steamed female Chinese mitten crab (Eriocheir sinensis) were extracted by a new type of adsorbent (MonoTrap), identified by gas chromatography-mass spectrometry (GC-MS) and determined by gas chromatography-olfactometry (GC-O). Ninteen key odor compounds (odor intensity value≥3) were obtained in Chinese mitten crab, among which trimethylamine (fishy), (Z)-4-heptenal (fishy) and 2-ethylpyridine (roasted potato) were found in all four edible parts of Eriocheir sinensis. In addition, 8 KOCs (2-ethylfuran, benzaldehyde, 1-octen-3-ol, 6-methyl-2-heptanone, 2-pentylfuran, (E,E)-3,5-octadien-2-one, nonanal and decanal) were also identified in the abdomen meat, 5 KOCs (toluene, 2,5-dimethylpyrazine, 1-octen-3-ol, (E,E)-3,5-octadien-2-one and 2-methylnaphthalene) in the claw meat, 3 KOCs (toluene, 2-nonanone and nonanal) in the leg meat, and 12 KOCs (1-penten-3-ol, toluene, hexanal, 1,3,5-octatriene, benzaldehyde, 1-octen-3-ol, 6-methyl-2-heptanone, 2-pentylfuran, (E,E)-3,5-octadien-2-one, nonanal, (E,Z)-2,6-nonadienal and decanal) in the gonad part.

Abstract: Objective: Cruciferous herb plant Weixian Radish (Raphanus Sativus L.), also known as Lai Fu, is a kind of popularly eatable fruit and vegetable. The present paper describes the isolation and characterization of two compounds isolated from Weixian Radish. Methods: The methanol extraction was separated by column chromatography. Obtained compounds were identified with physical and chemical properties and NMR. Results: Two compounds were isolated from the extract of Raphanus Sativus L. for the first time and their structures were identified as β-sitosterol and 1-O-(β-D-glucopyranosyl)-(2S, 3S, 4R, 8E)-2-[(2'R)-2'-hydroxyltetracos-15'-enoylamino]-8-octa-decene-1, 3, 4-triol, which have many biologically active effects.

Abstract: The volatile compounds in different edible parts (gonads, hepatopancreas) of raw and cooked Chinese mitten crab were extracted by a new type material (MonoTrap) and analyzed by gas chromatography-mass spectrometry (GC-MS). Totally 97 volatile compounds were identified by GC-MS and their odor characteristics were analyzed by ROAV values screen. There is a significant difference of odor-active compounds between male and female Chinese mitten crab. What’s more, the results indicated that the varieties and contents of volatile compounds in hepatopancreas were greater than in gonad. The results of ROAV values screen were summarized, 15 odor-active compounds whose ROAV values greater than 0.1and 9 key odor-active compounds whose ROAV values greater than 1 were further selected. The results indicated that decanal, trimethylamine, nonanal were the key odor-active compounds in hepatopancreas and gonads.